Round 12: Mayweather leaps in with two left hands. Wobbles Maidana with left-right. Maidana flurries, probably his best rush since midway through the fight. Mayweather counters follow up rush with left hand. Standing ovation at the final bell, both raise hands in victory. 10-9 Maidana

Round 7: Mayweather finishes combination on ropes, then lands in ring center. USA chant much louder all of a sudden. Mayweather lands three shots as Maidana leans along ropes, then spins off. Weeks breaks up clinch quickly. Mayweather lands two rights in ring center. Back to ropes, neither land much. 10-9 Mayweather

Round 5: Mayweather emerges with dab of grease over right eye. Begins round in center of ring. Maidana misses wild right, Mayweather counters with left to body. Maidana swings wild left, Mayweather blocks with right glove. Maidana lands right to body and forces action to ropes in final 10 seconds. 10-9 Maidana

Round 4: Maidana doing what series of opponents have claimed they'd do -- make Mayweather uncomfortable. Mayweather is landing clean blows as Maidana approaches, but nothing yet of significance. Chant begins again. Mayweather scores with two straight left hooks. Maidana pushes to ropes, works body. Mayweather dabs at eye, cut on right eyebrow. 10-9 Mayweather

Round 3: Mayweather scores with left and right as Maidana comes in. Mayweather shaking left arm after clinch as if it's hurt. Maidana scores with right uppercut along the ropes. Mayweather scores with straight right. Back to the ropes again, Maidana has flurry, little lands. 10-9 Maidana

Round 2: They're back along the ropes, Maidana lands left to the body and right to the head. Mayweather comes off with body shot. Mayweather regains space with jabs. Maidana looks arm weary. Chant begins again. 10-9 Mayweather

Round 1: Mayweather stays in pocket flurries. Maidana drives fight to ropes swings wildly, some landing some not. Mayweather lands low left late in round spins Maidana off. Best opposition round against him in a while. 10-9 Maidana

12:18 a.m. ET: Mayweather walking to the ring being rapped in by Lil' Wayne, escorted by Justin Bieber and amid a shower of bills falling from the ceiling bearing "Money's" image.

12:14 a.m. ET: Maidana is in the ring. "Chino" soccer chant competing with music over the P.A.

12:13 a.m. ET: Ring walks are beginning after the Mexican, Argentine and U.S. anthems.

12:10 a.m. ET: Khan says he's ready for Mayweather. Thinks his skillful style will present a more interesting fight for him than come-forward guys like Maidana, etc.

12 a.m. ET: The judges go even bigger, unanimously giving it to Khan by margins of 117-106, 119-104 and 119-104.

11:57 p.m. ET: It's over. Khan survives Collazo's grinding onslaught in the final three minutes and should stamp his ticket for a potential Mayweather fight. CBSSports.com gave Collazo the final round to make the final count, 115-110, for Khan.

11:53 p.m. ET: Elsewhere, Marcos Maidana will enter the ring in a little while as a big underdog -- with an emphasis on the word big. Unofficial locker room weigh-ins indicate Maidana has put on 18-1/2 pounds since Friday's weigh in and tips in tonight at 165. Mayweather gained two, and will come in at 148, according to Showtime's Chris DeBlasio.

11:48 p.m. ET: So much for momentum. Khan roared back in the 10th to score a pair of knockdowns, and, had the round lasted 30 seconds longer, might have gotten a stoppage. A big right hand dropped Collazo for the second time in a neutral corner and Khan flurried late, but ran short of time.

11:45 p.m. ET: We're through nine rounds and Collazo has certainly got momentum, though he's been unable to land a series of heavy blows to put Khan on the deck or in extended trouble. CBSSports.com has it 87-82 for Khan through nine, meaning he's likely in good shape if he stays on his feet for nine minutes.

11:42 p.m. ET: Collazo's best round of the night came in the eighth, though it began with him being docked a point for a flagrant low blow. He drilled Khan with a left at the 2-minute mark, and Khan was subsequently docked a point for excessive holding.

11:33 p.m. ET: At the halfway point, Collazo is doing a lot of stalking and the sense exists that he could trouble Khan with a clean shot, but he's not doing enough sustained damage to win rounds. Instead, Khan is landing cleaner and flashier punches, and has thus far been able to elude prologed danger.

11:25 p.m. ET: Some dramatics followed quickly in the fourth, when Khan punctuated an inside exchange with a short right hand that dropped Collazo. The New Yorker rallied, however, and shook Khan up with a left hand about midway through the round that had him moving and holding for the remainder of the round.

11:21 p.m. ET: It's been an effective, if not enthralling first nine minutes for Khan, who's landed well with a straight right hand to Collazo, showed superior hand speed in spurts and used his legs to elude any prolonged engagements. A very disciplined, successful outing through the fight's first quarter.

11:05 p.m. ET: Collazo weighed in at 147 pounds on Friday, but is in the ring at 163, according to Showtime. Khan also weighed in at 147 and is here tonight at 161.

11:04 p.m. ET: Luis Collazo and Amir Khan are in the ring for their scheduled 12-rounder for the nearly as ridiculous WBC silver welterweight championship. The winner, especially if it's Khan, is expected to move toward the front of the line for a shot at Mayweather, provided he does his part in the main event later tonight.

11:02 p.m. ET: Broner after his win: "The loss humbled me, but at the end of the day I'm still Adrien Broner."

10:58 p.m. ET: Seated just a few feet from press row and here in town to root on his countryman, Amir Khan, is former cruiserweight and heavyweight title claimant David Haye.

10:55 p.m. ET: Broner got his cherished hardware -- if anyone cherishes WBA international belts, that is -- by scores of 99-91, 98-92 and 100-90. "As you can see, I really didn't go through any trouble in that fight," he said, generating a chorus of boos. "It was a sparring match on TV." He followed up those preliminary remarks with a classless, "I just beat the f*ck out of a Mexican," which got him chastised by Showtime's Jim Gray, and ultimately ended by claiming he wants Manny Pacquiao before the Filipino leaves the scene.

10:50 p.m. ET: A few rugged exchanges in the final minute, but Broner presumably did what he needed to do to get back on the winning side. CBSSports.com sees him a 98-92 winner.

10:47 p.m. ET: Broner and Molina head to the final round with the outcome in little doubt. The former champion at 130, 135 and 147 pounds has controlled the action with a superior skill set, while also managing to irritate the crowd with his version of an "Ali shuffle" along with several exaggerated windup bolo punches. Barring something unforeseen, he'll cruise home.

10:31 p.m. ET: For the second time tonight, a thunderous "Chino" soccer chant erupted without noticeable provocation. Not quite as loud as last September's "Ca-Nel-O" rhythms, but decidedly louder than the segment of fans in attendance pulling for Mayweather.

10:30 p.m. ET: The fight has reached its halfway point and it's looking a lot better for Broner, who spent much of the third, fourth and fifth rounds strafing Molina with quick-handed combinations from the outside. He also scored with uppercuts when things got close, and was able to better evade the clubbing shots Molina was landing with early on.

10:18 p.m. ET: The second round proved difficult for Broner in the second straight fight. He avoided the canvas this time, unlike in December's match with Maidana, but did take a heavy overhand right that left him reeling backward to the ropes.

10:09 p.m. ET: Those boos you hear are greeting the ring entry of former three-division champion Adrien Broner, who'll face Carlos Molina in a scheduled 10-rounder for the WBA international super lightweight championship. Broner isn't popular in many circles, and it's especially one-sided against him here -- in a room full of people hoping to see favorites lose tonight.

10 p.m. ET: Love after his victory: "It was a very good fight. He had a very awkward style and I knew it was smart to take a knee (in the fifth),"

9:58 p.m. ET: The judges saw it largely the same way, giving Love a unanimous decision by scores of 95-93, 97-92 and 96-93 for the unbeaten new WBA international champion at 168. Love is 18-0, while Periban dipped to 20-2-1. He began his career with 20 straight wins and is 0-2-1 in his last three fights.

9:55 p.m. ET: It's a nice finish by Love, who rallied from his harrowing fifth round to cut and wobble Periban in the sixth before controlling most of the fight's second half. CBSSports.com sees him a 96-93 winner.

9:32 p.m. ET: It's getting ugly for the favorite, Love, through five rounds. He was rattled by heavy shots in the third, then dropped to a knee in the fifth after a prolonged battering that Jay Nady took a long look at before ultimately deciding not to step in. When Love sank to the floor, however, Nady's peeling away of Periban sent the Mexican sprawling headlong to a neutral corner.

9:30 p.m. ET: The arrivals of the two main event fighters were just shown on the arena's video screens. Footage of Maidana was greeted with soccer-style chants that rhythmically worked in his nickname, "Chino." The volume out-did that of Mayweather, who was shown smiling with his security guards.

9:12 p.m. ET: It's not often you'll see a fighter rocking the polo shirt into the ring, but that's what Periban is going with. Not sure it inspires confidence.

9:10 p.m. ET: Showtime has gone live to its podium panel and the music has begun for the first PPV ring walk. Mexican Marco Antonio Periban (20-1-1) faces "Money Team" member J'Leon Love (17-0) in a scheduled 10-rounder for something called the "Vacant WBA International Super Middleweight Championship." That's got to mean something good, right?

8:45 p.m. ET: The early undercard stoppage streak got to six when Tabiti drilled Shipman with a big overhand right that backed his man up and sent a stream of blood across the ring. Tabiti (6-0) pounced on Shipman (3-2) in a corner and landed the majority of thudding shots in a follow-up flurry that drew referee Mora's halt at 2:11 of round four. The PPV portion of the program will go live at 9 p.m. ET.

8:25 p.m. ET: The final pre-PPV match of the evening is headed toward the ring as Tabiti, another member of the "Money Team" and nicknamed the "Beast," risks an unbeaten mark in five fights in a scheduled six-rounder against Shipman, who's won three of four as a pro.

8 p.m. ET: Five fights, five quick endings as the card reaches the midway point. Gavril boosted his pro mark to 9-0 and scored his seventh stoppage when referee Russell Mora stepped in to stop the bout against Hendrix at 1:58 of round four.

7:55 p.m. ET: While the guys pining to be stars were operating in the ring, Golden Boy Promotions founder Oscar De La Hoya appeared for a Q & A session in the fight-week media room and discussed a recent schism between he and his company's CEO, Richard Schaefer. "No one is getting fired. I don't want him to leave," De La Hoya said of Schaefer, who's made comments indicating he's miffed at De La Hoya's recent attempts at reconciliation with rival promoter Bob Arum. "No one's telling him to leave."

7:43 p.m. ET: A 30-minute lull ends with the appearance of super middleweights Ronald Gavril (8-0) and Tyrell Hendrix (10-3-2) in the ring for a scheduled eight-rounder. This fight and one more -- matching cruiserweights Andrew Tabiti and John Shipman -- are the last two on the docket before the PPV portion of the program begins at 9 p.m. ET.

7:10 p.m. ET: Early stoppage night continues here in the desert as Ogogo lands a big right hand that drives Tapia to the ropes, then follows with a prolonged barrage to bring the wave-off from referee Jay Nady just 46 seconds into the third round. All four winners thus far have come from the blue corner, which will later be home to Mssrs. Love, Broner, Khan and Mayweather.

6:55 p.m. ET: In the ring for a scheduled six-round middleweight bout are unbeaten Englishman Anthony Ogogo (5-0) and Jonuel Tapia (8-4-1) from the Bronx. It's Ogogo's second fight in the United States, and first since he appeared in Atlantic City in May 2013. He was a bronze medalist for England in the 2012 Summer Olympics.

6:30 p.m. ET: It's three-for-three for the "Money Team" after Theophane pummeled Perez with a prolonged combination along the ropes, bringing a stoppage from referee Kenny Bayless at 2:44 of round four.

6:25 p.m. ET: The impromptu concert is over and Theophane and Perez are in the ring. Perez was dropped in the early going, but has rallied and landed a few decent shots of his own since rising.

6 p.m. ET: Two prelim fights that last a total of five rounds apparently necessitate a significant musical interlude. Carly Rae Jepsen followed by Robin Thicke at ear-numbing levels leaves a guy craving pretty much anything in the ring. As it stands, next up on the bout sheet is an eight-rounder between welterweights Ashley Theophane (34-6-1) and Angino Perez (15-4).

5:45 p.m. ET: Bellows lived up to his "KO" nickname, dropping Gifford once in the opening round, then effectively ending the night in the second when another right hand left Gifford reeling long enough to prompt final intervention from referee Jay Nady at 1:17.

5:30 p.m. ET: Next up on the agenda is a super middleweight six-rounder between Lanell Bellows (6-1-1) and Thomas Gifford (2-1-1). Bellows was unbeaten in his first seven fights before dropping a majority decision to Eddie Hunter in December.

5:25 p.m. ET: Miller upped his record to 2-0 with a KO victory when he dropped Colas (1-3) in a neutral corner and saw his opponent unable to rise after 58 seconds of round three. Miller is trained by former light heavyweight champion Eddie Mustafa Muhammad.

5:15 p.m. ET: Professional fights have broken out at the MGM Grand. Leading off what's scheduled to be a 10-bout card are junior welterweights Ladarius Miller and Richard Colas in a four-rounder. Miller, a member of Floyd Mayweather Jr.'s "Money Team" enters at 1-0 as a pro, while Colas was announced as 1-2 in three fights.

It wouldn't be a Floyd Mayweather Jr. fight week without some sidelights.

But the question heading into Saturday night's welterweight unification between the sport's pound-for-pound king and gritty Argentine Marcos Maidana is whether the sudden out-of-ring tumult will have any impact on “Money's” typically virtuoso work inside the ropes.

Mayweather will risk his World Boxing Council (WBC) version of the 147-pound championship at the MGM Grand in Las Vegas, while simultaneously vying for the World Boxing Association (WBA) title belt that Maidana won with a surprising unanimous decision over Adrien Broner in December.

The main event will top a four-bout Showtime pay-per-view card that will go live at 9 p.m. ET.

Preceding Mayweather and Maidana on the broadcast are a 10-round bout between super middleweights J'Leon Love and Marco Antonio Periban, a 10-rounder at junior welterweight matching a returning Broner against Carlos Molina and a 12-rounder at welterweight between a pair of potential Mayweather foils -- England's Amir Khan and Brooklyn native Luis Collazo.

Mayweather and Maidana are expected in the ring sometime after 11 p.m. ET.

The odds show Mayweather as a significant favorite -- it'd take a $1,000 wager to return $100 on him at VegasInsider.com, while a $100 outlay on Maidana would return $650 -- but his typically laser-like focus on the fight was questioned Thursday after an impromptu social media rant about an ex-girlfriend.

A since-deleted Facebook post to his official account showed what he claimed were sonograms of twin babies before the children's mother, Shantel Jackson, had an abortion; and a subsequent post, also deleted, suggested that Jackson had undergone plastic surgery that he'd paid for. An Instagram post, too, showed a photo of a bikini-clad Jim Carrey alongside another image that resembled Jackson.

Mayweather mentioned Jackson during the final pre-fight episode of Showtime's All Access documentary, which aired Wednesday, saying he was “making a major, major change” and that he wanted to “live right.” He also said that an unstable home life during his childhood skewed the way he perceived relationships, before adding “I'm ready for change and the only thing I can do is work at it.”

Whether the curiously timed missives were designed to boost chatter about Saturday's fight, or are signs that outside factors are impacting Mayweather's preparation for Maidana, no one's quite sure.

“Any distraction is motivation for (older fighters),” said WBA/IBF light heavyweight champion Bernard Hopkins. "We need that. We got everything else. We use every little thing to motivate us. I used to start arguing with people. I'd fire them and hire them back an hour later. These things that you don't actually plan and plot. The only chance Maidana has is if the distractions finally catch up."

TALE OF THE TAPE

Floyd Mayweather Jr.

Marcos Maidana

Record

45-0, 26 KOs

35-3, 31 KOs

Height

5-8

5-7

Reach

72 inches

69 inches

Weight

147 pounds

147 pounds

Age

37

30

Stance

Orthodox

Orthodox

Hometown

Grand Rapids, Mich.

Margarita, Argentina

Rounds

339

169

How does Mayweather win? The path to 46-0 heads in much the same direction as those that led to the first 45 wins over 18 professional years. Mayweather is the quicker and more precise of the two fighters, and his ability to stand in the pocket, elude shots and return his own has bamboozled many foes with designs on roughing him up and outslugging him. If he's successful at it again, he won't lose to Maidana.

How does Maidana win? More so than any Mayweather opponent since Arturo Gatti, Maidana has shown an ability to absorb terrific amounts of punishment before out-willing his opponents into submission. He was a big underdog against wannabe Mayweather clone Adrien Broner, but took “The Problem's” best shots and confounded him with heavy blows from all angles. That's his best game plan against “Money,” too.

Prediction: Mayweather by ninth-round TKO Though he was decked a couple times and hurt several more in his December encounter with Maidana, Broner was able to control stretches of the fight when he let his hands go -- and he scored particularly well with lead left hooks in those rounds. Mayweather is at least a level or two above Broner in terms of all-around game, and he'll gradually punish the Argentine until the referee intervenes in the ninth.

CBSSports.com will have live coverage of Mayweather vs. Maidana on Saturday, May 3. Come back for full fight results and analysis.